Crossword clues for spermatozoon
spermatozoon
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Spermatozoid \Sper`ma*to*zo"id\, n. [Spermatozo["o]n + Gr. e'i^dos form.] (Biol.) The male germ cell in animals and plants, the essential element in fertilization; a microscopic animalcule-like particle, usually provided with one or more cilia by which it is capable of active motion. In animals, the familiar type is that of a small, more or less ovoid head, with a delicate threadlike cilium, or tail. Called also spermatozo["o]n. In plants the more usual term is antherozoid.
Douglas Harper's Etymology Dictionary
Wiktionary
n. (context cytology English) A reproductive cell or gamete of a male, carried in semen, that fertilizes an ovum to produce a zygote.
n. (alternative spelling of spermatozoon English)
WordNet
n. the male reproductive cell; the male gamete; "a sperm is mostly a nucleus surrounded by little other cellular material" [syn: sperm, sperm cell, spermatozoan]
[also: spermatozoa (pl)]
Wikipedia
A spermatozoon (pronounced , alternate spelling spermatozoön; plural spermatozoa; from "seed" and "living being") is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, that normally develops into an embryo.)
Sperm cells contribute approximately half of the nuclear genetic information to the diploid offspring (excluding, in most cases, mitochondrial DNA). In mammals, the sex of the offspring is determined by the sperm cell: a spermatozoon bearing a X chromosome will lead to a female (XX) offspring, while one bearing an Y chromosome will lead to a male (XY) offspring. Sperm cells were first observed by Anton van Leeuwenhoek in 1677.
Usage examples of "spermatozoon".
If Pelly were one of the last to have Alfred that day, then we may conclude that she inadvertently transported his spermatozoa to your Lacey.
But then one should not forget that van Leeuwenhoek also looked at human semen, observed sperm, and described each individual spermatozoon as a perfectly formed, minuscule mannikin, thus reinforcing a long-held preformationist superstition about human reproduction that took at least another century to outgrow.
Between four and seven years he had seminal discharges, but it was not determined whether the semen contained spermatozoa.
They were biological engineers rather than scientists, their main concern being to improve the strains of their meat-producing and wool-bearing animals, descended in the main from the spermatozoa and ova which Lode Jumbukas did all colonisation vessels of her periodhad carried under refrigeration.
At first it was thought that the enzyme on the acrosome was being inhibited in some fashion and thus the spermatozoon was being prevented from penetrating the zona pellucida—the protective layer of the ovum— but a series of beautiful demonstrations by Russell and Austin at Cambridge proved beyond all doubt that not only could fertilization still take place outside the uterus, but that non-parthogenic cell division could still be induced in vitro at least as far as the morula stage.
The human genome is about 3,120,000,000 base pairs long, so half of that is in each spermatozoa -- 1,560,000,000 base pairs .
The car about to smash into you, the bullet on its way to your brain, the first cancer cell about to break loose, the boss reaching for the phone to call you in so he can fire you, the spermatozoon about to be launched toward the ovum, the final insult about to be hurled at the once, and perhaps still, beloved, the final drink of alcohol which would rupture the abused blood vessel, the decision which would lead to the light that would surely fail?
When a spermatogonium was observed to change to a primary spermatocyte-still diploid-it would be segregated and at the instant it divided into two secondary spermatocytes-haploids, one with an X chromosome and one with a Y chromosome-they would be again segregated and each would be encouraged to develop into spermatozoa.
She also had deep lacerations to the scalp, a minor abrasion to the upper lid of her right eye and her vaginal smear was positive for spermatozoa.